From 0a6e593487844fd00920c0caab64aa98eac368a1 Mon Sep 17 00:00:00 2001 From: Eduardo Habkost Date: Thu, 26 Jul 2018 17:19:04 +0100 Subject: [PATCH 14/14] i386: Allow TOPOEXT to be enabled on older kernels RH-Author: Eduardo Habkost Message-id: <20180726171904.27418-12-ehabkost@redhat.com> Patchwork-id: 81534 O-Subject: [qemu-kvm RHEL8/virt212 PATCH v2 11/11] i386: Allow TOPOEXT to be enabled on older kernels Bugzilla: 1597739 RH-Acked-by: Paolo Bonzini RH-Acked-by: Laurent Vivier RH-Acked-by: Igor Mammedov From: Babu Moger Enabling TOPOEXT feature might cause compatibility issues if older kernels does not set this feature. Lets set this feature unconditionally. Signed-off-by: Babu Moger Message-Id: <1528939107-17193-2-git-send-email-babu.moger@amd.com> [ehabkost: rewrite comment and commit message] Signed-off-by: Eduardo Habkost (cherry picked from commit f98bbd8304112187cafc3e636c31b2a3865d2717) Signed-off-by: Eduardo Habkost Signed-off-by: Danilo C. L. de Paula --- target/i386/kvm.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 6e66f9c..bb5e485 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -371,6 +371,13 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, if (host_tsx_blacklisted()) { ret &= ~(CPUID_7_0_EBX_RTM | CPUID_7_0_EBX_HLE); } + } else if (function == 0x80000001 && reg == R_ECX) { + /* + * It's safe to enable TOPOEXT even if it's not returned by + * GET_SUPPORTED_CPUID. Unconditionally enabling TOPOEXT here allows + * us to keep CPU models including TOPOEXT runnable on older kernels. + */ + ret |= CPUID_EXT3_TOPOEXT; } else if (function == 0x80000001 && reg == R_EDX) { /* On Intel, kvm returns cpuid according to the Intel spec, * so add missing bits according to the AMD spec: -- 1.8.3.1